White furs and method of producing the same



Patented Apr. 30, 1940 UNITED STATES WHITE FURS AND METHOD or PRODUCING THE SAME David C. Pisarev, Bethlehem, Pa., assignor of I one-third to Edwin C. Weiskopf, New York, N. Y., and one-third to Harry M. Ullmann,

Bethlehem, Pa.

No Drawing.-

8 Claims.

This invention relates to the processing of furs and, more particularly, to the treatment of pelts, including the fur thereof, which are intended to be white.

Heretofore, in processing fur pelts to obtain white furs, the products have been unsatisfactory because an undesirable shade of white, usually yellowish or greyish, both with respect to the hair and the skin of the pelt, was obtained. I have discovered that in processing furs which are intended to be white or substantiallywhite, greatly improved results with respect to the whiteness of the fur and the elimination of off-colors, for example, the yellowish or greyish tints heretofore obtained, can be realized by subjecting suitable pelts, such as those heretofore utilized in the production of so-called "white furs, to treatment with a weaksolution of chromium salts, I have found that the pelts thus treated are completely free from the undesirable oiI-colors or shades in the finished fur, among which are yellowish and greyish shades, and the resulting product is decidedly and strikingly whiter than products resulting from prior processes. This was very surprising because chromium salts have heretofore been considered entirely harmful to the production of white furs from pelts and every effort in the way of factory cleanliness and otherwise has been made to avoid any and all chromium salts in the processing of white or substantially white furs, and when such furs were desired, white alum or formaldehyde has been used in the tanning process, to the exclusion ofall chromium J salts in the tanning process as well as in other stages of the process of producing the white furs,

although certain chromium salts have been employed for tanning purposes in making dark colored furs from pelts. I

In carrying out the process in accordance with my invention, I prefer to use suitable chromium salts in a solution containing t to A5 of one per cent (by weight) of chromium salt, although for speedy treatments a somewhat stronger solution, say up to one per cent, may be utilized or required. Among the chromium salts, which are suitable and which I prefer to use is chromium alum (chromium potassium sulphate), although there may be utilized certain other chromium compounds, such as chromium nitrate, chromium sulphate, chromium chloride and chromium ammonium sulphate. Such compounds may be utilized, in accordance with my invention, in a weak solution in the manner described herein to impart to the pelt a degree of whiteness which is highly desirable and, more particularly, such Application February 5, 1938, Serial No. 188,989

whiteness which may be characterized as a clear bluish white as distinguished from the yellowish or greyish white of the so-called white furs produced by previous processes.

In'practicing the present invention in accord- 5 ance with the preferred form thereof, I prefer to treat the pelts prior to the tanning thereof, as best results are obtained by this mode of treatmeant, but I may combine this treatment with and perform the same concurrently with the tan- 1o ning process by including in the tanning liquid the soluble chromium compound in the proportion hereinabove specified, because even when the pelts are thus treated in the tanning process as distinguished from the preliminary treatment, 15 and without the latter, furs of a superior whiteness are obtained as compared with furs produced in accordance with prior methods. In the tanning process, white alum or formaldehyde is customarily utilized as heretofore, but other suitable go tanning-agents may be used.

In performing the process in accordance with the present invention, I utilize naturally white pelts in the condition in which they arecustomarily provided in their stage of manufacg5 ture just prior to the tanning process. These pelts, either when subjected to the preliminary treatment with the weak solution of chromium compound as hereinabove described or when treated during the tanning thereof,'are left in the 30 solution and the latter is preferably maintained at a temperature of about 90 F. for about fortyfive minutes, with such agitation as may be required for an even distribution of the chromium salt or other chromium compound. The tem- 35 perature of the solution, however, and the duration of the immersion of the pelts therein may vary considerably, for example, the temperature of the solution may vary from F. up to and even higher than F. to a temperature which, 40 however, is low enough to prevent injury to the pelt. The time during which the pelts are immersed depends, to some extent, upon the temperature of the solution and the concentration thereof, depending upon the effect desired and 5 it will be readily appreciated that, in general, the time of immersion will be less as the temperature and/or strength of the solution is increased.

While I have disclosed the preferred manner of practicing my invention, it will be understood 5 that variations in the process herein specifically disclosed may be made and will occur to those skilled in the art, particularly in view of the present disclosure. Therefore, I do not wish to be limited precisely to the processes herein'descrlbed, 55

except as may be required by the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. In a process of producing white furs, that improvement which comprises treating suitable naturally white fur pelts carrying the fur hair with a weak solution of a chromium compound of the group consisting of chromium potassium sulphate, chromium nitrate, chromium sulphate, chromium chloride and chromium ammonium sulphate, whereby the fur hair has a decided whiteness devoid of yellowish or grayish tinges.

2. In a process of producing White furs, that improvement which comprises treating suitable naturally white fur pelts, in the state in which the fur pelts carrying the fur hair are conditioned for tanning, with a weak solution of chromium alum.

3. In a process of producing white furs, that improvement which comprises treating suitable naturally white fur pelts, in the state in which the pelts carrying the fur hair are conditioned for tanning, with a solution containing chromium alum in an amount less than about 1% by weight.

4. In a/process of producing white furs, that improvement which comprises treating suitable naturally white fur pelts and the fur thereof, in the state in which the pelts carrying the fur hair are conditioned for tanning, with asolution containing chromium alum in an amount between about .05%:and about .40% by weight.

5. In a process of producing white furs, that improvement which comprises treating suitable naturally white fur pelts and the fur thereof, in the state in which the pelts carrying the fur hair are conditioned for tanning, with a solution containing a chromium compound of the group consisting of chromium potassium sulphate, chromium nitrate, chromium sulphate, chromium chloride and chromium ammonium sulphate.

6. A white fur treated with a substance which imparts a light bluish tinge to the fur hair whereby said fur hair has a decided whiteness as compared with an off-color yellowish or greyish- White, said substance being comprised in the group consisting of chromium potassium sulphate, chromium nitrate, chromium chloride, chromium sulphate, and chromium ammonium sulphate.

7. A white fur having a surface deposit or coating of a substance which imparts a light bluish tinge thereto whereby the fur hair has a decided whiteness as compared with an off-color yellowish or grayish-white, said substance being.

comprised in the group consisting of chromium potassium sulphate, chromium nitrate, chromium chloride, chromium sulphate, and chromium ammonium sulphate.

8. .A white fur treated with a chromium compound, such as chromium alum, which imparts a light bluish tinge to the fur hair whereby said fur has a decided whiteness as compared with an oiT-color yellowish or greyish-white.

DAVID C. PISAREV. 

